Artificial limb.



PATENTBD APR. 10, 1906.

4N T A N E V m M m 0V m NI 3 A M m AB IH BOP SIN 0P0 M, MM m P P A Toall whom it concern.-

Be it known that I, RUnoLF.RsENxRA1vZ,

UNITED STATES Parana? ()FFICE.

, RU-DoLr RosENKnANz; or rn'rssuse, PENNSYLVANIA. ARTIFICIAL LINIB.

a citizen of the" United States, residing at Pittsburg, in the State ofPennsylvania, have inyented certain new and useful Im rovements inArtificial Limbs, of which t 'e following is a specification.

; My invention relates to artificial legs and Especially to the jointconnecting the leg and the foot. The objects of the invention are,

l to provide a superior universal joint between the: main part of theartificial leg and its lower extremity; to provide a joint which willclosely simulate in action the natural joint. of theankl; toavoid jarupon the-stump when the limb is brou 'ht in contact with the awingwherein-+- .5

j as

ground an'd to simp ify and to strengthen and generally im rove theconstruction of artificial limbs. hese objects and other advantageswhich will hereinafter ap ear, I attain by-nieans of, the construction 1lustrated in preferred forms in the accompanying Figure 1 is'a centralvertical section through anartificial leg and foot having my improvement -Fi es 2 jand 3 are-respectively, a central longliltu alsection,and a plan view, of the cus 'onmeinber of. the joint showing analternate construction of the cushion, and i Figure is a central sectionof-amodified form of the limb for use when the footmhst be directlyjoined to the lower end of the':ar

tificial leg. I

Primarily I-avoid the use of hinges and sliding partsin the joint byproviding a cushs the intermediate resistance of t e cushion block 9which is preferably made of rubber. The bolt 7 extends throughthiscushion block 7 and has a spherical head which works in a videsocket formed by two semi-spherical plates 11 and 11" both of which arescrewed to the foot ortion 5.. In the socket may be proif some pocketsof gra hite 12, or other lubricatingmaterial, and t e rubber cushion 9is maintained in position by means of Dins Specification of LettersPatent.- 1 Application filed March 1, 1905. Serial l'o. 247.856;

Patented April 10,1900.

' '13 fixed in. the flat faces of 'the twowooden portions5'and'6l v Thecushion block 9 has at its forward side a rtion 9" which is of denserstructure of ru ber so as to provide greater resistance when'thepressure comes u on this portion by the tilting forward-of t e-legportion 6 with respect to the foot portion 5, so that as the 'tiltingproceeds the resistance becomes greater and greater in order to simulatethe natural action .of the foot as much as ossible and make the jointmost resilient at the rear. The? bolt 7' ordinarily is not required tomove at-all since the cushion-block 9 allows for all variations ofdistance betweenthe surfaces of the leg portion and the foot portion,the leg moving about the ball 10 as a center. The 'bolt 7' may be kepttightand noise avoided by use of a rubber washer 14"plaoedunderthe locknutat the top as shown.

In Figures 2and 3 is shown an alternate construction ,of the'cushionblock 9 in which Y 'the eater iesistance'necessaryin the forwar portionis provided by an inserted block'l5 of harder rubber than the remainderof the'liod'y,having the same effect-as the denser portion 9"in.. thefirst form described.

In Figure 4 'isshown amodification .of the devices adaptedtotheus'eofishchllimbs de-.

ed to accommodate-l cut ofi at theans'i I '85 k e, or justabove1,'inwhic' case there is not much room in the le g'portion to fixthe bolt 7 audit is therefore inverted andthe socket is placed on theuppe'i' side of the cushion block 9. As shown, the leg art22 has at thebottom a plate19 throng hich pass some riv- 'ets20,holdin the t .0 lates17 and 18 which areuse to form t esocket for the head ofthe bolt. Inthis case also thebolt 7 is secured -by a lock nut andjunderneath it Ithere is a cushion of rubber 21in the portion 5, as in the firstinstance;

It will be seen th by this construction the footportion has a universaljoint with.

the leg portion so that it maytilt laterally, and 'move forward andback, and in either 'motionit is resisted by the resiliency 'of therubber, block 9; also that in the ordin' tilting motion of the leg inwalking, the b ock 9 providesa heavier resistance on the front than onthe back and this resistance will increaseiigigreater ratio by reason ofthe denser structure of the rubber between the two forward surfaces ofthe leg ortion 6 and the 'foot 5. Since thebolt 7' oes not have any noslidie motion in its sheath it is not required to be fubrieated and isentirely out of contact with any portion which mi ht make noise, beingsurrounded by a leat icr tube 8 and resting on the rubber washer, whichalso; maintains a snw fit of the hall lO'iu its; socket 12. It will beseen also that there are no parts which catigct out of order as the 1parts are all held in proper position by the 1 weight upon the limb, andthere are no movi ing parts except the revolution of the ball 10 l inits socket and this cannot make any noise I and requires only thelubrication that can be 3 sn )plied by the graphite inserts therein. Itwill also be seen that the parts are readily assembled or can be takenapart or can be easily interchanged, and the resistance of tlte joint tobending can bc t'efltltttttl by varying the amount of the dense portionof the rubber. in any motion of the foot the entire effect of weight ofthe leg-is met with a resilient cushion and all jarring is ptvoided.Other advantage of the structure will readily occur to those familiarwith the'art.

Having thus described my invention and illustrated its use,.what lclaitn as new, and desire to secure by Letters Patent, is the following:

1. An artificial limb comprising a leg portion and a foot portion and anintermediate rubber portion continuous in outer contour with the othertwo said portions and entirelv separating them, and a universalball-andsocket joint connecting the two solid portions by parts passingthrough the rubber portion, substantiallv as descrtbed..

2. ln an artificial leg the combination with a leg port ion and a footportion, and connecting means to hold them together each portion havinga flat joint surface, of a rubber cushion between said portions'ext-entlin" over the entire area of said flat surfaces am fixed in theleg portion, extending throughthe said rubber portion, a ball on thesame and an engagin socket on the foot portion, said rubber cushionhaving the forward end made of denser rubber than the rest, to affordgreater resistance to compression, substantially as described.

4. An artificial leg having ale g portion and a foot portion of solidmaterial, an inter-- vening block of rubber entirelv covering thesurfaces of said portions and being continuous with the other partsin'outline, whereby. there is no moving joint. between the footand legportion, and a non-metallic sheath and a rod therein having a headmaking a universal joint between the foot and leg pprtions allow tngfree compression of said ru ber pad, subst a ntially as described. I I

5. In an'artifieial limb a cushion for spacing at )art the foot and legportions composed of soft rubber which has an integral forward part ofit made more dense than the restto afford reater resistance at theforward side of the foot, substantially as described.

In testimony whereof I have hereunto. signed my name in the presence ofthe two subscribed witnesses. I

R UDOLF ROSENKRANZ'.

Witnesses:

Aaeuwoa'rn MARTIN.

